Propane Hot Water Heaters for Cabins, Garages and Whole Homes

When a cabin sits beyond the reach of natural gas lines, or a workshop needs a utility sink that actually runs warm, propane is often the fuel that makes hot water possible. The best propane hot water heaters deliver enough flow for the fixtures you use at once, vent safely for where they are installed and light reliably in cold weather. Most buyers choose between a compact outdoor-friendly unit for a single faucet and a larger indoor tankless model for a whole house.

The five models below mix portable outdoor units and wall-mounted tankless heaters. Everything said about each one comes from its name and category, so verify flow rate, venting, gas connection and clearance requirements on the manufacturer page before buying. As of 2026, the key habit is to size by flow and temperature rise, not by marketing claims, and to have a licensed installer handle gas piping and venting.

Quick Picks

How to Choose

Size by flow rate and temperature rise

The two numbers that matter are gallons per minute and the temperature rise the heater can deliver. Subtract your incoming water temperature from the target of about 120 degrees. In a cold northern climate where groundwater runs near 40 degrees, you need an 80 degree rise. A shower uses roughly 2 gallons per minute, a kitchen faucet about 1.5, so a household running two showers at once should plan on at least 4 to 5 gallons per minute at that rise.

Check the gas input and supply line

Propane heaters are measured in BTUs per hour, and bigger units may require a larger gas line and a regulator that can deliver enough pressure. Small portable units connect to a standard 20-pound grill-style cylinder, while whole-home models usually connect to a larger tank. Confirm the model is made or converted for propane, since a natural gas unit will not run safely on liquid propane without the correct kit.

Match venting to the install location

Indoor units need safe exhaust, either through sealed direct-vent pipes or through a power vent. Outdoor-rated units skip the vent runs but must be shielded from freezing temperatures. As a rule, never install an unvented heater inside a closed space, and make sure a carbon monoxide alarm sits near sleeping areas. Local code often requires permits and a licensed professional for gas work.

Think about maintenance and cold-weather use

Hard water leads to scale on the heat exchanger, so units in hard-water areas benefit from a flush every year. Look for models with freeze protection or plan to drain them in winter. Check that replacement parts and service are easy to find, and keep the manual handy for error codes. A good warranty on the heat exchanger is a useful sign of build quality. Ask whether the unit shuts off automatically if the flame goes out, and whether it has overheat protection, since both are basic safety features for any gas appliance. Finally, find out how often the tank must be refilled by your propane supplier: a larger household can burn through a small cylinder in a few days, so a bulk tank or a supplier contract may be the more practical setup.

Our Picks Reviewed

Rinnai V65iP

Rinnai is a major tankless brand, and the V65iP name carries the iP indoor propane suffix. One pro is that a purpose-built propane model avoids the conversion kits that natural gas units need. A second pro is that tankless heaters provide hot water on demand instead of keeping a tank heated all day. The con is that indoor installation requires venting and professional gas work, which raises the upfront effort. Skip it if you want a plug-and-play heater for a camp site, or if you cannot run exhaust pipe through a wall. It suits homeowners with a propane supply who want a reliable on-demand heater in a utility room. Ask the installer to confirm the gas line size and vent route before you buy, since those two items drive most of the installation effort.

Eccotemp L5

Eccotemp sells portable tankless heaters, and the L5 sits in its compact line. One pro is portability: a compact outdoor heater can serve a camp shower, a rinse station or a garage utility sink. The second is that portable propane heaters work without household gas lines, using a standard propane cylinder. The con is that a compact portable heater will not supply multiple fixtures at once, and it needs protection from freezing. Skip it if you need hot water for a whole house or for simultaneous showers, or if you plan to use it indoors. It suits cabins, RVs, job sites and outdoor kitchens. Keep the unit in an open, ventilated spot, away from tents and enclosed spaces, and drain it fully before a freeze to avoid cracked internal parts.

Eccotemp i12-LP

The LP in this name means liquid propane, and the i12 indicates an indoor model in the Eccotemp range. One pro is the propane-ready label, which reduces confusion about fuel type. A second pro is that an indoor tankless heater delivers on-demand water for small homes, apartments or cabins. The con is that indoor installation needs proper venting and a safe gas connection, so it is not a quick weekend project for most people. Skip it if you want a heater for a campsite or an outdoor shower, or if you need whole-home capacity for a large family. It suits small cabins and workshops that need modest hot water. Install a carbon monoxide alarm nearby and confirm the exhaust path is sealed and sloped correctly, because poor venting is the main safety risk with indoor gas appliances.

Marey GA10LP

Marey makes tankless gas heaters, and the GA10LP name includes LP for liquid propane. The first pro is that a propane-labeled model is ready for a standard propane supply without extra conversion. The second is that smaller tankless units suit apartments and small homes where space is tight. The con is that smaller models may not keep up with multiple showers at once, especially in cold climates with a large temperature rise. Skip it if you have a large family or several bathrooms in use together, or if you cannot vent the unit correctly. It suits small households and guest cottages with light hot-water demand. Compare the flow at your winter incoming water temperature before buying, since small units lose output fastest in cold ground water.

Rheem RTGH-95DVLP

Rheem is a well-known water heater manufacturer, and the model code includes DV for direct vent and LP for liquid propane. One pro is that direct-vent designs use sealed pipes, which keep exhaust away from living areas. A second pro is that a whole-home tankless unit saves floor space compared with a large tank. The con is that tankless installation, gas line upgrades and venting require a qualified installer, which can complicate budgeting. Skip it if you want a portable heater, or if your gas supply cannot handle the larger line size. It suits homeowners replacing a tank with a propane-fired whole-house tankless heater. Have the gas line, regulator and vent run inspected before purchase so the first day of installation does not reveal costly surprises.

Which One Fits

• Remote cabin with one bathroom: Marey GA10LP or Eccotemp i12-LP, both labeled for liquid propane and sized for light demand rather than a busy family morning.
• Camp shower, RV or job site: Eccotemp L5, a portable choice that moves with you and needs only a propane cylinder and a water source.
• Whole-home swap from an electric tank: Rheem RTGH-95DVLP.
• Utility room with a propane tank outside: Rinnai V65iP.
• Comparing more models: see our companion roundup of propane water heaters for tankless picks with different specs.

Common Mistakes

• Buying a natural gas model and assuming it will run on propane without a conversion kit.
• Sizing by tank gallons instead of flow rate and temperature rise.
• Skipping the carbon monoxide alarm near the heater and sleeping areas. Test it monthly, replace it on the schedule printed on the unit, and treat any alarm as a reason to shut off the heater and ventilate right away.
• Installing a portable unit indoors, where there is no safe exhaust path. Outdoor-rated portable heaters belong in open air, away from windows, vents and enclosed spaces.
• Ignoring scale buildup in hard-water areas, which shortens the heater's life. A yearly vinegar flush or a water softener upstream keeps the heat exchanger clear and the flow steady.

FAQ

Is propane cheaper than electric for hot water?

It depends on local rates. Propane heats quickly and works when power is out, but check your regional fuel costs.

Can I install a propane heater myself?

Gas lines and venting should be handled by a licensed installer, and many areas require permits.

How big a propane tank do I need?

Small portable heaters run from 20-pound cylinders, while whole-home units typically need larger tanks that a supplier can refill. As a rough guide, a household with two bathrooms often sets up a 250 to 500 gallon tank, though your supplier can size one to your usage and local rules about tank placement, distance from the house and buried or above-ground installation.

Do these heaters work in cold weather?

Many do, but outdoor installs need freeze protection. Drain portable units before winter, and insulate exposed supply lines so a cold snap does not crack fittings. Indoor units in an unheated garage or crawlspace face the same risk and may need heat tape or relocation.

Can I use a propane heater with a pool or spa?

Pool heaters are separate products. If you maintain a pool, see our pool vacuum for above ground pool guide for cleaning tools.